{"id":37006,"date":"2022-10-20T00:00:00","date_gmt":"2022-10-20T00:00:00","guid":{"rendered":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/?post_type=purple_issue&p=37006"},"modified":"2023-03-30T09:02:43","modified_gmt":"2023-03-30T09:02:43","slug":"the-missing-moon-of-saturn","status":"publish","type":"post","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/2022\/10\/20\/the-missing-moon-of-saturn\/","title":{"rendered":"The missing moon of Saturn"},"content":{"rendered":"\n
BULLETIN <\/span><\/h5>\n\n

The missing moon of Saturn<\/h2>\n\n

The moon could explain two of the planet\u2019s biggest mysteries \u2013 its tilt and its rings <\/span><\/p>\n\n

\"\"
 Saturn\u2019s trademark rings could be the rubble of a moon wrecked 160 million years ago, leaving the planet with its distinctive lean <\/figcaption><\/figure>\n\n

It sounds like <\/strong>the premise for a science fiction novel, but Saturn could have a long-lost moon. The moon, called Chrysalis by researchers, may have broken apart 160 million years ago to create the planet\u2019s majestic rings. <\/p>\n\n

\u201cJust like a butterfly\u2019s chrysalis, this satellite was long-dormant and suddenly became active, and the rings emerged,\u201d says Jack Wisdom from MIT, who led the study. <\/p>\n\n

The origin of Saturn\u2019s rings has been a long-standing question in planetary science. Over the last decade, there has been mounting evidence that the rings are a lot younger than the planet and have potentially only existed for 100 million years or so. The reason we can see them so well from Earth is because the planet is at a 26.7\u00b0 angle. This tilt is thought to be due to a gravitational tug-of-war between Saturn and its neighbour Neptune, called a resonance. To be sure, however, requires knowing how Saturn\u2019s mass is distributed \u2013 something that the planet\u2019s rings make very difficult to measure. It was only when NASA\u2019s Cassini spacecraft flew between the rings and the planet during its Grand Finale in 2017 that the measurement could be taken.<\/span><\/p>\n\n

With this in hand, researchers soon realised that Saturn was in reality just outside a resonance with Neptune \u2013 as if they had previously been in sync but were no longer. Wisdom\u2019s team set out to find what could have pushed the two out of step, first suspecting one of Saturn\u2019s 83 moons. Computer simulations showed this wasn\u2019t the case, but did reveal that removing a moon changed Saturn\u2019s tilt. <\/p>\n\n

They then began investigating to see the effect of a lost moon, which was how they discovered Chrysalis. Initially about the size of Iapetus, Saturn\u2019s current third-largest moon, Chrysalis would have become gravitationally unstable around 100 to 200 million years ago. Once it strayed too close to Saturn, the planet\u2019s gravity would rip the moon apart, creating icy debris that went on to form the rings. \u201cIt\u2019s a pretty good story, but like any other result it will have to be examined by others,\u201d says Wisdom. \u201cBut it seems that this lost satellite was just a chrysalis waiting to have its instability.\u201d www.mit.edu<\/a> <\/p>\n\n

<\/p>\n\n

Photos: NASA\/JPL-CALTECH\/SPACE SCIENCE INSTITUTE, NASA\/JOEL KOWSKY, NASA\/ESA\/CSA\/A CARTER (UCSC) THE ERS 1386 TEAM AND A. PAGAN (STSCI), GEMINI OBSERVATORY\/ARTWORK BY LYNETTE COOK. <\/p>\n","protected":false},"excerpt":{"rendered":"

The moon could explain two of the planet\u2019s biggest mysteries \u2013 its tilt and its rings <\/p>\n","protected":false},"author":24,"featured_media":37005,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ub_ctt_via":"","purple_page_number":"12","purple_custom_meta_purple_page_number":"12","purple_seq_number":"1","purple_custom_meta_purple_seq_number":"1","purple_source_article":"article_12-1.xml","purple_custom_meta_purple_source_article":"article_12-1.xml","purple_source_issue":"November-2022","purple_custom_meta_purple_source_issue":"November-2022","purple_external_id":"November-2022-12-1","purple_custom_meta_purple_external_id":"November-2022-12-1","purple_issue_code":"|0000086558||","purple_custom_meta_purple_issue_code":"|0000086558||","purple_android_product":"com.im.skyatnight.210","purple_custom_meta_purple_android_product":"com.im.skyatnight.210","purple_ios_product":"com.im.skyatnight.210","purple_custom_meta_purple_ios_product":"com.im.skyatnight.210","purple_web_product":"","purple_custom_meta_purple_web_product":"","purple_publication_id":"075fab74-0a21-4201-866a-899d6c41c40c","purple_migrated":"","kt_blocks_editor_width":""},"categories":[19],"tags":[14],"featured_image_src":"https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/10\/70b4f174-d386-474d-aee7-2274ab206798.jpg","author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/author\/importmanagerhubsprylab-com\/"},"acf":{"readingTimeMinutes":"3","apple_news_title":""},"uagb_featured_image_src":{"full":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/10\/70b4f174-d386-474d-aee7-2274ab206798.jpg",2048,1189,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/10\/70b4f174-d386-474d-aee7-2274ab206798-150x150.jpg",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/10\/70b4f174-d386-474d-aee7-2274ab206798-300x174.jpg",300,174,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/10\/70b4f174-d386-474d-aee7-2274ab206798-768x446.jpg",768,446,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/10\/70b4f174-d386-474d-aee7-2274ab206798-1024x595.jpg",800,465,true],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/10\/70b4f174-d386-474d-aee7-2274ab206798-1536x892.jpg",1536,892,true],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/10\/70b4f174-d386-474d-aee7-2274ab206798.jpg",2048,1189,false]},"uagb_author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/author\/importmanagerhubsprylab-com\/"},"uagb_comment_info":0,"uagb_excerpt":"The moon could explain two of the planet\u2019s biggest mysteries \u2013 its tilt and its rings","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/37006"}],"collection":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/users\/24"}],"replies":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/comments?post=37006"}],"version-history":[{"count":7,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/37006\/revisions"}],"predecessor-version":[{"id":37786,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/37006\/revisions\/37786"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media\/37005"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media?parent=37006"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/categories?post=37006"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/tags?post=37006"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}